Something in the air

June 10, 2013

Do you have allergies? If so, did your allergies become worse after the 2011 flood? Have you gone in for allergy testing from a doctor certified in allergy and immunology?

Dr. Michael Reder, physician in allergy and immunology at Trinity Health, has gathered some statistics on allergy cases post-2011 flood. He took every single skin test that he has administered to patients and calculated the percentage of every skin test that showed positive to mold. However, he didn't separate the tests of those people who are allergic in general and those who are not, Reder noted. Therefore, the numbers are potentially skewed by the non-allergic people, since they never would've been influenced in the first place. The percentages on the graph represent 40 to 50 allergy tests per month, he added. Unfortunately, though, Reder said that since he just arrived to Trinity Health in April 2011, there wasn't enough time to get a really accurate look. Also, it was hard to find generalizations in mold, he added, because doctors don't study it.

According to Reder's statistics, the percentage of skin tests with positive mold allergies showed a 29 percent average from April 2011 to June 2013.

Article Photos

Jill Hambek/MDNDr. Michael Reder, physician in allergy and immunology at Trinity Health, is shown in an exam room at Health Center-Medical Arts. He has recently gathered some statistics on allergy cases since the 2011 flood.

Jill Hambek/MDNThis graph, created by Dr. Michael Reder, shows the percentage of skin tests that have shown positive to mold allergies spanning from April 2011 to June 2013. The average percentage of positive tests to mold allergy in people was 29 percent.

The number of people coming in to see Reder about their allergies since the flood has been steady, he said. When it comes to allergies, though, allergens are usually thought of as pollens. It takes a few seasons for the person to become acclimated to pollens, he explained, and the same is thought about molds. However, mold allergies after flooding have never been looked at, Reder said.

It would be helpful to have multiple years of allergy studies in order to see any trends, Reder said.

"If (Reder's current study) stays in the same range for the next five years, then we can say the flood was not an effect on allergies," Reder explained. "If it goes down in less time, then it would be."

In general, there was an anticipation that the 2011 flood would bring an increase in mold sensitization in allergic people, but that it would not happen until a year after, Reder said. An increase doesn't happen instantly, he added. No one knows how long it takes to become sensitized to mold. Mold counts are pretty stable until there's an event like a flood, but it is unknown what the general mold levels were in the air at the time.

"There are so many variables," Reder said. "It's hard to say if the flood affected anything." But, according to the chart, he added, if allergies increased after the flood, then it happened very rapidly, within a month.

Shortly after the flood, Reder said he had people asking about allergy problems, and he also has people believing their allergies became worse after the flood. He noted that during the clean-up stages of the flood, he didn't see any toxic rates in high doses of mold, or infections or higher rates in allergies.

"People took precautions and we got the word out about protecting their faces," he said.

Reder said he could not pinpoint if more people have been coming in for allergy testing since the flood.

"It's hard to say," he said. "Everyone feels like nasal symptoms are allergies, but they don't know because they've never been tested. The only way they'll get treated is to come in for testing."

It's possible that people's allergies got worse from or since the flood, Reder added, but not certain.

Allergies in this region are typically from grass, weeds and mold. A lot of that is due to North Dakota's topography. There are a lot of grasslands here and those affect seasonal allergy patterns.

"Allergies will be less or worse depending on where you live," Reder said.

An important aspect to note about Reder's statistics is that he did not see a major increase of mold allergies in people as a result from the flood, he said, despite what most people would have expected. Reder added that his results were limited by not having a lot of data prior to the flood.

Atypically, if there was a rise, it would be over a short duration," Reder said. "You wouldn't see the entire allergy population being allergic forever, either."